What you need to know about Moderna’s new COVID vaccine, just approved by the FDA

The shot had previously been approved for everyone 12 and older. Now, there are limits.

Jun 2, 2025 - 19:39

What you need to know about Moderna’s new COVID vaccine, just approved by the FDA

Moderna, over the weekend, announced that the U.S. Food and Drug Administration had approved its second-generation COVID vaccine, but only for specific populations: all adults 65 and over and those between 12 and 64 with at least one underlying risk factor as defined by the Centers for Disease Control and Prevention.

Moderna’s COVID shot had previously been approved for everyone 12 and older.

The narrower approval follows the FDA announcing it was likely to limit access to immunizations among healthy children and adults under 65 this fall—as well as an announcement by Health Secretary Robert F. Kennedy (who, in 2021, called mRNA shots the “deadliest vaccine ever made”) about how COVID shots would be removed from the federal vaccine schedule for children and pregnant women. Still, days later, the CDC issued its own updated advice, going against Kennedy’s announcement by keeping the shots on the schedule for healthy children 6 months and older.

The mNEXSPIKE vaccine, which is meant to be a booster but will not immediately replace the Moderna’s original COVID shot, was found through a Phase 3 clinical trial of 11,400 participants to be superior to the original; it showed a 9.3% higher relative vaccine efficacy (rVE) in individuals 12 and older and a 13.5% higher rVE in adults 65 and older.

It will be available to those in the eligible populations—including those with risk factors such as asthma, chronic lung or kidney disease, or diabetes, according to the CDC—in the 2025-2026 respiratory virus season.

The limits worry some physicians, including Associate Professor of Pediatrics, Microbiotics and Immunology at the University of Rochester Dr. Jennifer Nayak, who told Rochester First, “We know that children who are hospitalized with COVID-19, about 41% of them don’t have a known preexisting condition,” Nayak said. “When you limit vaccination to only children who have preexisting conditions, you’re going to miss some of the children who will get more seriously ill with this virus.”

How the new vaccine works differently

This updated mRNA shot still works by teaching the body to make a specific protein that helps your immune system ward off certain diseases.

But instead of targeting the entire spike protein on the virus’s surface, reports Medical Xpress, the new vaccine focuses on just two segments. This helps it last longer when refrigerated, making it easier to distribute in certain parts of the world, and is more effective at lower doses.

Possible side effects of the new Moderna vaccine

In the clinical trial, the new vaccine was found “to have a similar safety profile” to the original, with “fewer local reactions and comparable systemic reactions,” the most common being injection site pain, fatigue, headache, and myalgia.

Still, other possible risks listed by Moderna, which “may not be all the possible side effects,” include:

Severe allergic reaction (which would occur within one hour) that could cause trouble breathing, face or throat swelling, body rash, fast heartbeat, or dizziness
Myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the heart’s outside lining, especially in males age 12-24; symptoms include chest pain, shortness of breath, and feelings of a fluttering or pounding heart

Such reactions, Moderna suggests, can be reported to the Vaccine Adverse Event Reporting System (VAERS).

“The FDA approval of our third product, mNEXSPIKE, adds an important new tool to help protect people at high risk of severe disease from COVID-19,” said Stéphane Bancel, Chief Executive Officer of Moderna, in a company news release. “COVID-19 remains a serious public health threat, with more than 47,000 Americans dying from the virus last year alone.”